<?php
  
  /*
   * This file is part of the Assetic package, an OpenSky project.
   *
   * (c) 2010-2014 OpenSky Project Inc
   *
   * For the full copyright and license information, please view the LICENSE
   * file that was distributed with this source code.
   */
  
  namespace Assetic\Cache;
  
  /**
   * Interface for a cache backend.
   *
   * @author Kris Wallsmith <kris.wallsmith@gmail.com>
   */
  interface CacheInterface
  {
      /**
       * Checks if the cache has a value for a key.
       *
       * @param string $key A unique key
       *
       * @return Boolean Whether the cache has a value for this key
       */
      public function has($key);
  
      /**
       * Returns the value for a key.
       *
       * @param string $key A unique key
       *
       * @return string|null The value in the cache
       */
      public function get($key);
  
      /**
       * Sets a value in the cache.
       *
       * @param string $key   A unique key
       * @param string $value The value to cache
       */
      public function set($key, $value);
  
      /**
       * Removes a value from the cache.
       *
       * @param string $key A unique key
       */
      public function remove($key);
  }